If there is an engineering argument, I'm guessing it's to do with multi-threaded DOM+JS, given the mention of multi-process architecture. Also, how much does A

If there is an engineering argument, I'm guessing it's to do with multi-threaded DOM+JS, given the mention of multi-process architecture. Also, how much does Apple really control WebKit? At a glance, it looks to me like FOSS. (Apple might be the maintainer, but it seems trivial to fork it in a different direction.) Perhaps this is a more nebulous "thought leadership" kind of thing?